Surgical Implant Devices and Methods for Their Manufacture and Use

ABSTRACT

A sealable vascular system includes an endovascular implant to be delivered in a compressed or folded state to an implantation site. The endovascular implant includes a tubular implant body and a sealable circumferential collar at said tubular implant body and including a variable sealing device and a control lead traversing from said variable sealing device to a user for controlling said variable sealing device by the user, said variable sealing device and said control lead being cooperatively operable to reversibly expand and contract said sealable circumferential collar such that said sealable circumferential collar is circumferentially adjustable during deployment thereof to achieve a repositionable fluid-tight seal between said sealable circumferential collar and the internal walls of the implantation site.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims is a divisional application of U.S.patent application Ser. No. 11/888,009 (Pub. No. 2009/0005760), filedJul. 31, 2007 (which application claims priority of U.S. ProvisionalPatent Application Ser. No. 60/834,401, filed Jul. 31, 2006 and U.S.Provisional Patent Application Ser. No. 60/834,627, filed Aug. 1, 2006),the entire disclosures of which are hereby incorporated herein byreference in their entireties.

FIELD OF THE INVENTION

The present invention relates to the field of vascular surgery and thetreatment of aneurysms or other luminal vascular defects. Specifically,the present invention relates to a novel design for sealableendovascular implants and to methods of use for such implants inendovascular procedures for aneurysms of the thoracic or abdominal aortaor other vascular structural defects.

BACKGROUND OF THE INVENTION

Aneurysms of the thoracic and abdominal aorta represent a degenerativeprocess of the aorta that is often attributed to atherosclerosis.Aneurysms are defined as a focal dilatation with at least a 50% increaseover normal arterial diameter, usually associated with a degradation ofthe aortic media, or other structural defect in the aortic wall.

Medical research has suggested that these lesions are prone to occur inareas subjected to significant redirection of blood flow duringdiastole; however, the exact cause of such aneurysms is not known. Afamilial tendency to symptomatic aneurysms has been suggested.Degenerative aneurysms account for more than 90% of all infrarenalaneurysms of the abdominal aorta. Other potential causes includeinfection, cystic medial necrosis, arteritis, trauma, collagen vasculardisorders, and anastomotic disruption.

Abdominal aortic aneurysms most commonly begin in the infrarenal aorta,and extend down to the iliac bifurcation. Aneurysms of the thoracicaorta are most commonly located in the descending thoracic aorta,beginning just distal to the origin of the left subclavian artery.

Aortic aneurysms generally affect elderly Caucasian men. Aorticaneurysms are less commonly reported among persona of African American,Asian, and Hispanic heritage. Abdominal aortic aneurysms are five timesmore common in men than in women. In men, the aneurysm process appearsto begin at approximately age fifty years and reaches peak incidence atapproximately age eighty years. Women appear to have a more delayedonset in which the aneurysm process appears to begin at approximatelyage 60 years. Smoking has been associated as a potential risk factor forthe development of aortic aneurysms. Other risk factors include previousaneurysm repair or peripheral aneurysm (such as femoral or popliteal),coronary artery disease, and hypertension.

Although the reported findings from autopsy series vary widely, theincidence of aortic aneurysms probably exceeds 3-4% in individuals olderthan 65 years. Death from aneurysmal rupture remains one of the 15leading causes of death in the United States. In addition, the overallprevalence of aortic aneurysms has increased significantly in the last30 years. This is partly due to an increase in diagnosis based on thewidespread use of imaging techniques. However, the prevalence of fataland nonfatal rupture has also increased, suggesting a true increase inincidence. An aging population probably plays a significant role.

The surgical management of aortic aneurysms dates back to the earlytwentieth century, and has involved a variety of methods, includingligation, intraluminal wiring, cellophane wrapping, homografts, andgrafts using nylon and polytetrafluoroethylene [PTFE] fabrics.

Prior to the development of endoaneurysmorrhaphy in 1962, postoperativesurgical mortality rates were high (>25%). Endovascular repairtechniques have reduced the operative mortality to 1.8-5%.

Existing techniques for endovascular treatment of aneurysms involveplacement of a tubular graft with seals to normal aortic walls above andbelow the aneurysm to create a tubular bridge to carry flow across theaneurysm without allowing flow to fill the aneurismal sac. Using thesetechniques, grafts may be placed using percutaneous access to thefemoral arteries, and delivery/implantation using vascular catheters andfluoroscopic visualization. The deficiencies associated with existingendograft technology relate to leakage at the graft/aortic interfaceand/or post-implantation migration of the endograft. Smallpost-implantation leaks may be repaired with the placement of one ormore extension cuffs above the endograft proximally, or below theimplant distally to attempt to obtain a better seal with the vessel. Therequired use of such cuffs may add significantly to the overall cost andmorbidity of the procedure. Major failures with endograft repairgenerally require emergent open surgery to avert catastrophic rupture ofthe aneurysm. Also, current endovascular systems require accurate sizematching of endograft implants, leaving a very small margin for error.

In order for a patient to be a candidate for existing endograft methodsand technologies, a proximal neck of at least 15 mm. of normal aortamust exist between the origin of the most inferior renal artery and theorigin of the aneurysm in the case of abdominal aneurysms or the leftsubclavian artery for thoracic aortic aneurysms in order to permit anadequate seal. Similarly, at least 15 mm. of normal vessel must existdistal to the distal extent of the aneurysm for an adequate seal to beachieved.

Migration of existing endografts has also been a significant clinicalproblem, potentially causing leakage and re-vascularization of aneurysmsand/or compromising necessary vascular supplies to arteries such as thecarotid, subclavian, renal, or internal iliac vessels. This problem hasbeen partially addressed by some existing endograft designs, in whichbarbs or hooks have been incorporated to help retain the endograft atits intended site. However, these existing endograft designs are notremovable and repositionable once they are deployed. Thus, once such anendograft has been placed, open surgery is necessary if there is failuredue to leakage or undesired occlusion of other vascular structures.

Because of the limitations imposed by existing vascular endograftdevices and endovascular techniques, approximately eighty percent ofabdominal and thoracic aneurysms repaired in the U.S. are still managedthough open vascular surgery, instead of the lower morbidity of theendovascular approach.

SUMMARY OF THE INVENTION

The present invention is directed towards a novel design forendovascular implant grafts, and methods for their use for the treatmentof aortic aneurysms and other structural vascular defects. A sealable,repositionable endograft system for placement in a blood vessel isdisclosed, in which an endograft implant comprises a non-elastic tubularimplant body with an elastic proximal end(s) and an elastic distalend(s). Both the elastic proximal and distal ends in an implantaccording to the present invention further comprise one or morecircumferential sealable collars and one or more variable sealingdevice, capable of controllably varying the expanded diameter of saidcollar upon deployment to achieve the desired seal between the collarand the vessel's inner wall. An endovascular implant according to thepresent invention further comprises a central lumen and one or morecontrol leads extending distally from releasable connections with eachvariable sealing device. Embodiments of endovascular implants accordingto the present invention may further be provided with retractableretention tines or other retention devices allowing an implant to berepositioned before final deployment. An endograft system according tothe present invention further comprises a delivery catheter with anoperable tubular sheath, capable of housing a folded or compressedendograft implant prior to deployment and capable of retracting orotherwise opening in at least its proximal end to allow implantdeployment, said sheath sized and configured to allow its placement viaa peripheral arteriotomy site, and of appropriate length to allow itsadvancement into the thoracic or abdominal aorta, as required for aspecific application.

In use of an embodiment according to the present invention, an operatorprepares an arteriotomy site in a patient in a suitable peripherallocation, such as the femoral arteries. Upon incision into the artery, aguide wire is placed, and extended under radiographic visualization intothe aorta. A catheter sheath is inserted, housing a collapsedendovascular graft. An injector cannula is inserted, with its proximaltip extending beyond the catheter sheath. Under radiographicvisualization, radio-opaque or other contrast dye is injected into theinjector cannula, and the contrast dye-enhanced view is used to positionthe proximal edge of the cannula above the beginning of the aneurysmsac. The catheter sheath is then partially retracted to expose theproximal portion of the endovascular implant. Through action initiatedby the operator on the control leads, the variable sealing device forthe proximal seal is activated, expanding the elastic circumferentialsealable collar until firm contact is made with the vessel wall. At thispoint, additional radio-opaque or other contrast dye is injected, andthe seal is assessed. If there are leaks, the variable sealing device isagain activated to expand the diameter of the circumferential sealablecollar for a firmer contact. The seal is reassessed and adjusted untilthere no contrast dye leaks are seen. If the radio-opaque or othercontrast dye indicates that the device is placed too proximally andthreatens or covers the renal or subclavian junctions, then it isloosened and moved distally.

Once the proximal circumferential sealable collar has been suitablysealed, the catheter sheath is then retracted beyond the distal extentof the aneurysm exposing the remainder of the graft. The variablesealing device for the distal seal is similarly activated, expanding theelastic circumferential sealable collar until firm contact is made withthe vessel wall. At this point, additional radio-or other contrast dyeis injected, and the distal seal is assessed. If there are leaks, thedistal variable sealing device is again activated to expand the diameterof the distal circumferential sealable collar for a firmer contact. Theseal is reassessed and adjusted until there no contrast dye leaks areseen.

For an implant for an abdominal aortic aneurysm according to the presentinvention, an endograft implant comprises a non-elastic tubular bodywith an elastic proximal and distal ends and a non-elastic contralateralcuff. An operator deploys and seals the proximal and distal ends of theimplant as described above, with the distal end deployed and sealed inthe iliac artery on the side of the initial arteriotomy. Then, a secondarteriotomy is made on the opposite side. Radio-or other contrast dyeinjection is again used to allow visualization of the non-elasticcontralateral cuff, and a second guide wire is placed from the secondarteriotomy site through the non-elastic contralateral cuff. Acontralateral delivery catheter is then introduced over the second guidewire. The contralateral delivery catheter comprises a slidable orremovable sheath housing a folded or compressed endograft segmentalimplant which further comprises a non-elastic tubular body with anelastic proximal and distal ends. Both the elastic proximal and distalends in an endograft segmental implant according to the presentinvention further comprise one or more circumferential sealable collarsand one or more variable sealing device, capable of controllable varyingthe expanded diameter of said collar upon deployment to achieve thedesired seal between the collar and the non elastic contralateral cuffproximally and between the collar and the vessel's inner wall distally.An endograft segmental implant according to the present inventionfurther comprises a central lumen and one or more control leadsextending distally from releasable connections with each variablesealing device.

Again, under radiographic control, radio-opaque or other contrast dye isinjected into the injector cannula, and the contrast dye-enhanced viewis used to position the proximal edge of the contralateral deliverycatheter within the lumen of the non-elastic contralateral cuff. Thecontralateral delivery catheter sheath is then partially retracted toexpose the proximal portion of the endograft segmental implant. Throughaction initiated by the operator on the control leads, the variablesealing device for the proximal seal is activated, expanding the elasticcircumferential sealable collar until firm contact is made between thesealable collar and the non elastic cuff. At this point, additionalradio-opaque or other contrast dye is injected, and the seal isassessed. If there are leaks, the variable sealing device is againactivated to expand the diameter of the circumferential sealable collarfor a firmer contact. The seal is reassessed and adjusted until there nocontrast dye leaks are seen.

Finally, once the proximal circumferential sealable collar of theendograft segmental implant has been suitably sealed, the cathetersheath is then retracted beyond the distal extent of the aneurysm,exposing the remainder of the graft. The variable sealing device for thedistal seal is similarly activated, expanding the elasticcircumferential sealable collar until firm contact is made with thevessel wall. At this point, additional radio-opaque or other contrastdye is injected, and the distal seal is assessed. If there are leaks,the distal variable sealing device is again activated to expand thediameter of the distal circumferential sealable collar for a firmercontact. The seal is reassessed and adjusted until there no contrast dyeleaks are seen. At this point, the operator may remove the injectorcannula and detach the control leads from the variable sealing devices,and remove the control leads and guide wires from their arteriotomysites and close the wounds.

The preceding description is presented only as an exemplary applicationof the devices and methods according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side perspective view of the proximal tip of a deliverycatheter containing a disclosed embodiment of the present invention of acompressed or folded bifurcated endovascular implant with acontralateral cuff housed within a sheath.

FIG. 1B is a side perspective view of the proximal tip of a deliverycatheter containing a disclosed embodiment of the present invention of adecompressed or unfolded endovascular implant removed from a sheath.

FIG. 2A is a side perspective view of the proximal tip of a deliverycatheter containing a disclosed embodiment of the present invention of acompressed or folded endograft segmental implant housed within a sheathof the present invention.

FIG. 2B is a side perspective view of the proximal tip of a deliverycatheter containing a disclosed embodiment of the present invention of adecompressed or unfolded endograft segmental implant removed from asheath of the present invention.

FIG. 3 is a side perspective view of a disclosed embodiment of thepresent invention of an endograft segmental implant.

FIG. 4 is a perspective anatomic view of a disclosed embodiment of thepresent invention in which the proximal tip of an implant deliverycatheter placed in a first side through a femoral artery is positionedin an abdominal aorta in an infrarenal location, but above the origin ofan abdominal aortic aneurysm.

FIG. 5 is a perspective anatomic view of the disclosed embodiment of thepresent invention of FIG. 4 in which an injector cannula has beenintroduced through a lumen of the implant delivery catheter, andprotrudes proximal to the tip of the implant delivery catheter to fullyexpose all injector ports for radio-opaque contrast dye injectiontherethrough.

FIG. 6 is a perspective anatomic view of the disclosed embodiment of thepresent invention of FIG. 5 in which the sheath of the implant deliverycatheter has been retracted or partially opened to allow the endograftimplant therein to partially decompress or unfold, to expose theproximal elastic implant end and a length of the non-elastic tubularbody.

FIG. 7 is a perspective anatomic view of the disclosed embodiment of thepresent invention of FIG. 6 in which the implant delivery catheter hasbeen slightly withdrawn under radiographic control to position theproximal tip of the implant distal to the origins of the renal arteriesto preserve flow therein.

FIG. 8 is a perspective anatomic view of the disclosed embodiment of thepresent invention of FIG. 7 in which operator action on one or morecontrol leads connected to one or more variable sealing devices hascaused the extended circumferential sealable collar of the implant'selastic proximal end to firmly and fully contact the inner wall of theaorta, effecting a vascular seal therein.

FIG. 9 is a perspective anatomic view of the disclosed embodiment of thepresent invention of FIG. 8 in which operator action has fully retractedor opened and removed the sheath of the implant delivery catheterallowing the endograft implant therein to fully decompress or unfold, toexpose a distal elastic implant end and a non-elastic contralateralcuff.

FIG. 10 is a perspective anatomic view of the disclosed embodiment ofthe present invention of FIG. 9 in which operator action on one or morecontrol leads connected to one or more variable sealing devices hascaused the extended circumferential sealable collar of the implant'selastic distal end to firmly and fully contact the inner wall of thecommon iliac artery above the origin of the internal iliac artery,effecting a vascular seal therein and preserving flow through theinternal iliac artery.

FIG. 11 is a perspective anatomic view of the disclosed embodiment ofthe present invention of FIG. 10 in which operator action has placed ahooked second guide wire to grasp and stabilize the non-elasticcontralateral cuff under radiographic visualization through an accessvia a second side through a femoral artery.

FIG. 12 is a perspective anatomic view of the disclosed embodiment ofthe present invention of FIG. 11 in which operator action has placed acontralateral delivery catheter over the second guide wire.

FIG. 13 is a perspective anatomic view of the disclosed embodiment ofthe present invention of FIG. 12 in which operator action has removedthe sheath of the contralateral delivery catheter allowing the endograftsegmental implant therein to fully decompress or unfold, to expose aproximal segmental elastic implant end, a distal segmental elasticimplant end, and the full length of the non-elastic segmental tubularimplant body connecting said ends.

FIG. 14 is a perspective anatomic view of the disclosed embodiment ofthe present invention of FIG. 13 in which operator action on one or morecontrol leads connected to one or more variable sealing devices hascaused the extended circumferential sealable collar of the implant'sproximal segmental elastic implant end to expand to firmly and fullycontact the inner walls of the non-elastic contralateral cuff effectinga proximal seal, and then similarly caused the extended circumferentialsealable collar of the implant's distal segmental elastic implant end toexpand to firmly and fully contact the inner wall of the common iliacartery on the second side above the origin of the internal iliac artery,effecting a vascular seal therein and preserving flow through theinternal iliac artery.

FIG. 15 shows an diagrammatic view of a patient in a dorsal supineposition, with a disclosed embodiment of an endovascular implantaccording to the present invention in sealed position in the patient'sabdominal aorta proximally and distally, and with arteriotomy incisionsin both femoral arteries with an injector cannula and proximal anddistal control leads in place in the patient's right arteriotomy sitefor radiographic contrast dye injection and a second guide wire in placein the patient's left arteriotomy site, corresponding to the proceduralstage shown in FIG. 11.

FIG. 16 is a longitudinal anatomic view showing a disclosed embodimentof a thoracic endovascular implant according to the present invention insealed position proximally and distally in a patient's descendingthoracic aorta.

FIG. 17 is a longitudinal anatomic view showing an alternate disclosedembodiment of a thoracic endovascular implant in a patient's descendingthoracic aorta according to the present invention in which a firstthoracic endovascular implant with a non-elastic distal cuff has beensealed in position proximally and distally has been joined by a secondthoracic endovascular implant with a non-elastic tubular body with anelastic proximal end and an elastic distal end, both containingcircumferential sealable collars and variable sealing devices capable ofachieving a desired seal between the collar and the vessel's inner wall.

FIG. 18A is a side perspective view of the disclosed embodiment of anendovascular implant according to the present invention in which theproximal and distal circumferential sealable collars are provided withretractable retention tines and shown in a retracted, pre-deploymentposition.

FIG. 18B is a cross-sectional view of a disclosed embodiment accordingto the present invention of a proximal or distal circumferentialsealable implant collar with retention tines covered by a compressiblefoam sheathing in a retracted, pre-deployment position.

FIG. 19A is a longitudinal anatomic view of a disclosed embodimentaccording to the present invention of an endovascular implant which isbeing deployed and sealed proximally in an abdominal aorta containing aninfrarenal aneurysm, with incomplete distal circumferential sealableimplant collar expansion and seal at this stage of the procedure.

FIG. 19B is a cross-sectional view of the distal circumferentialsealable implant collar in FIG. 19A, showing the compressible foamsheathing covering the collar's retention tines within a vessel's lumen.

FIG. 20A is a longitudinal anatomic view of a disclosed embodimentaccording to the present invention of an endovascular implant which isbeing deployed and sealed proximally in an abdominal aorta containing aninfrarenal aneurysm, with complete proximal circumferential sealableimplant collar expansion and seal at this stage of the procedure.

FIG. 20B is a cross-sectional view of the proximal circumferentialsealable implant collar in FIG. 20A, showing compression of thecompressible foam sheathing allowing the collar's retention tines tocontact and engage the aortic wall circumferentially.

FIG. 21A is a perspective view of an embodiment of a variable sealingdevice according to the present invention.

FIG. 21B is a sectional view of an embodiment of a variable sealingdevice according to the present invention, in which the mechanism is ina released, locked state.

FIG. 21C is a sectional view of an embodiment of a variable sealingdevice according to the present invention, in which the mechanism is inan engaged, unlocked state.

FIG. 21D is a perspective view of an embodiment of a sealable collarcontaining a variable sealing device according to the present invention.

FIG. 22A is a longitudinal anatomic view of a disclosed embodimentaccording to the present invention of an endovascular implantincorporating an endograft monitoring device attached to the aneurysmalsac wall and the outer wall of the endograft in which the endograft hasbeen effectively sealed in position proximally and distally to ananeurysm, thus devascularizing the aneurysmal sac to allow the walls ofthe aneurysm to collapse against the endograft, and hold the endograftmonitoring device in a collapsed position.

FIG. 22B is a longitudinal anatomic view of a disclosed embodimentaccording to the present invention of an endovascular implantincorporating an endograft monitoring device of FIG. 22A in which theaneurysmal sac has become revascularized, allowing the endograftmonitoring device to spring open such that it may be visualized on x-rayor other diagnostic visualization means.

FIG. 22C shows an alternate embodiment of an endovascular implantincorporating an endograft monitoring device according to the presentinvention, in which said endograft monitoring device comprises more thanone spring-like attachment to both the outer wall of the endograft andto the inner wall of the aneurysmal sac, and in which the aneurysmal sachas been sealed and devascularized, allowing the walls of the aneurysmto collapse against the endograft, and hold the endograft monitoringdevice in a collapsed position.

FIG. 22D shows the alternate embodiment of an endovascular implantincorporating an endograft monitoring device according to the presentinvention of FIG. 22C, in which said endograft monitoring devicecomprises more than one spring-like attachment to both the outer wall ofthe endograft and to the inner wall of the aneurysmal sac, and in whichthe aneurysmal sac has become revascularized, allowing the endograftmonitoring device to spring open such that it may be visualized on x-rayor other diagnostic visualization means.

FIG. 22E shows yet another an alternate embodiment of an endovascularimplant incorporating an endograft monitoring device according to thepresent invention, in which said endograft monitoring device comprises aplurality of spring-like attachment to both the outer wall of theendograft and to the inner wall of the aneurysmal sac, and in which theaneurysmal sac has been sealed and devascularized, allowing the walls ofthe aneurysm to collapse against the endograft, and hold the endograftmonitoring device in a collapsed position.

FIG. 22F shows the embodiment of an endovascular implant incorporatingan endograft monitoring device according to the present invention ofFIG. 22E, in which said endograft monitoring device comprises more thanone spring-like attachment to both the outer wall of the endograft andto the inner wall of the aneurysmal sac, and in which the aneurysmal sachas become revascularized, allowing the endograft monitoring device tospring open such that it may be visualized on x-ray or other diagnosticvisualization means.

DETAILED DESCRIPTION OF INVENTION

The present invention may be understood more readily by reference to thefollowing detailed description of the preferred embodiments of theinvention and the examples included herein. However, before thepreferred embodiments of the devices and methods according to thepresent invention are disclosed and described, it is to be understoodthat this invention is not limited to the exemplary embodimentsdescribed within this disclosure, and the numerous modifications andvariations therein that will be apparent to those skilled in the artremain within the scope of the invention disclosed herein. It is also tobe understood that the terminology used herein is for the purpose ofdescribing specific embodiments only and is not intended to be limiting.

Unless otherwise noted, the terms used herein are to be understoodaccording to conventional usage by those of ordinary skill in therelevant art. In addition to the definitions of terms provided below, itis to be understood that as used in the specification and in the claims,“a” or “an” can mean one or more, depending upon the context in which itis used.

The present invention is directed towards novel designs for sealable andrepositionable endovascular implant grafts, and methods for their usefor the treatment of aortic aneurysms and other structural vasculardefects.

In an exemplary embodiment according to the present invention, asealable vascular endograft system for placement in a vascular defect isprovided, comprising an elongated main implant delivery catheter with anexternal end and an internal end for placement in a blood vessel withinternal walls. In such an exemplary embodiment, the main implantdelivery catheter further comprises a main implant delivery cathetersheath which may be openable or removable at said internal end and amain implant delivery catheter lumen containing within a compressed orfolded endovascular implant. Further in such an exemplary embodiment, anendovascular implant comprises a non-elastic tubular implant body withan elastic proximal end terminating in a proximal sealablecircumferential collar controlled by a proximal variable sealing devicewhich is operated by a proximal control lead that traverses said mainimplant delivery catheter and exits at said external end for interfaceby an operator, such that said proximal sealable circumferential collarmay be expanded or contracted by said operator to achieve a fluid-tightseal between said proximal sealable circumferential collar and theinternal walls of said blood vessel proximal to said vascular defect.Moreover, in such an exemplary embodiment, an endovascular implantfurther comprises a non-elastic tubular implant body with an elasticdistal end terminating in a distal sealable circumferential collarcontrolled by a distal variable sealing device which is operated by adistal control lead that exits said main implant delivery catheter atsaid external end for interface by an operator, such that said distalsealable circumferential collar may be expanded or contracted by saidoperator to achieve a fluid-tight seal between said distal sealablecircumferential collar and the internal walls of said blood vesseldistal to the vascular defect.

Referring now in more detail to the drawings, in which like numeralsindicate like elements throughout the several views, FIG. 1A shows aside perspective view of the proximal tip of a main implant deliverycatheter 100 with a main implant delivery catheter lumen 102 containinga disclosed embodiment of compressed or folded endovascular implant 200housed within a main implant delivery catheter sheath 104. Theendovascular implant 200 in the embodiment shown in FIG. 1A includes anon-elastic tubular implant body 106 with an elastic proximal end 108and an elastic distal end 110. The elastic proximal end 108 terminatesin a proximal sealable circumferential collar 112, controlled by aproximal variable sealing device 116 which is operated by a proximalcontrol lead 120 that traverses the main implant delivery catheter 100and exits distally for interface with an operator (not shown in FIG.1A). The elastic distal end 110 terminates in a distal sealablecircumferential collar 114, controlled by a distal variable sealingdevice 118 which is operated by a distal control lead 122 that exits themain implant delivery catheter 100 distally for interface with anoperator (not shown in FIG. 1A).

The embodiment of an endovascular implant 200 of FIG. 1A is furthershown in FIG. 1B removed from the main implant delivery catheter 100 andin a semi- or partially expanded or non-folded state. In addition to theelements described in FIG. 1A, the endovascular implant 200 in theembodiment shown in FIG. 1B may also include a contralateral non-elasticcuff 126.

An alternate embodiment of a sealable endovascular implant according tothe present invention is shown in FIG. 2A. The proximal tip of a mainimplant delivery catheter 100 with a main implant delivery catheterlumen 102 containing a disclosed embodiment of compressed or foldedstraight endovascular implant 202 housed within a main implant deliverycatheter sheath 104. The endovascular implant 202 in the embodimentshown in FIG. 2A includes a non-elastic tubular implant body 106 with anelastic proximal end 108 and an elastic distal end 110. The elasticproximal end 108 terminates in a proximal sealable circumferentialcollar 112, controlled by a proximal variable sealing device 116 whichis operated by a proximal control lead 120 that traverses the mainimplant delivery catheter 100 and exits distally for interface with anoperator (not shown in FIG. 2A). The elastic distal end 110 terminatesin a distal sealable circumferential collar 114, controlled by a distalvariable sealing device 118 which is operated by a distal control lead122 that exits the main implant delivery catheter 100 distally forinterface with an operator (not shown in FIG. 2A).

The embodiment of an endovascular implant 202 of FIG. 2A is furthershown in FIG. 2B removed from the main implant delivery catheter 100 andin an semi- or partially expanded or non-folded state. A straightendovascular implant 202 according to the embodiment shown in FIGS. 2Aand 2B provides a non-branching conduit between the proximal sealablecircumferential collar 112 and the distal sealable circumferentialcollar 114.

An embodiment of an endograft segmental implant according to the presentinvention is shown in FIG. 3. An endograft segmental implant 306sealably interfaces to provide a conduit between a non-elastic vasculargraft and a distal blood vessel. As shown in FIG. 3, an endograftsegmental implant 306 includes a non-elastic tubular segmental implantbody 308 with an elastic proximal segmental end 310 and an elasticdistal segmental end 312. The elastic proximal segmental end 310terminates in a proximal segmental sealable circumferential collar 314,controlled by a proximal segmental variable sealing device 318 which isoperated by a proximal segmental control lead 322 that traverses asegmental implant delivery catheter (not shown in FIG. 3) and exitsdistally for interface with an operator (not shown in FIG. 3). Theelastic distal segmental end 312 terminates in a distal sealablesegmental circumferential collar 316, controlled by a distal segmentalvariable sealing device 320 which is operated by a distal segmentalcontrol lead 324 that exits a segmental implant delivery catheterdistally for interface with an operator (not shown in FIG. 3).

In various embodiments according to the present invention, endovascularimplants 200 may be constructed of solid, woven, non-woven, or meshmaterials such as, but not limited to, natural or synthetic rubbers,nylon, Goretex, elastomers, polyisoprenes, polyphosphazenes,polyurethanes, vinyl plastisols, acrylic polyesters,polyvinylpyrrolidone-polyurethane interpolymers, butadiene rubbers,styrene-butadiene rubbers, rubber lattices, Dacron, PTFE, malleablemetals, other biologically compatible materials or a combination of suchbiologically compatible materials in a molded, woven, or non-wovenconfiguration, coated, non-coated, and other polymers or materials withsuitable resilience and pliability qualities. In certain preferredembodiments according to the present invention, it is desirable for thenon-elastic tubular implant body 106 and corresponding structures to bepliable to allow for folding or compressibility without allowingelasticity. In certain preferred embodiments according to the presentinvention, it is desirable for the elastic proximal end 108 and theelastic distal end 110 and corresponding structures to be both elasticand compressible or foldable. In any given preferred embodiment, thenon-elastic tubular implant body 106, the elastic proximal end 108, theelastic distal end 110 and corresponding structures may be constructedof the same material of varying elasticity, or these structures may beconstructed of different, but compatible materials.

FIGS. 4-9 illustrate an exemplary embodiment of sealable endovascularimplants and an illustrative method of their use according to thepresent invention for the treatment of an infrarenal abdominal aorticaneurysm with vascular access through bilateral femoral arteriotomysites.

In FIG. 4 a main implant delivery catheter 100 has been placed in afirst side through a femoral artery (not shown in FIG. 4) and positionedin an abdominal aorta 402 in a location distal to the renal arteries408, but above the origin of an abdominal aortic aneurysm 410.

FIG. 5 is a continuation of the disclosed embodiment of the presentinvention of FIG. 4 in which an injector cannula 404 with one or moreinjection ports 406 has been introduced through a main implant deliverylumen 102 of the main implant delivery catheter 100, and protrudesproximal to the tip of the implant delivery catheter 100 to fully exposethe injector ports 406 for real-time visualization contrast dyeinjection therethrough. Such contrast dye injection may be performedusing radio-opaque or other contrast dyes for fluoroscopy, computerizedtomography, or other radiographic techniques. In alternate embodimentsaccording to the present invention, other real-time visualizationtechniques may be used, including but not limited to, ultrasound ornuclear magnetic resonance techniques using appropriate contrast dyematerials for injection. Such contrast dye injection allows an operatorto assess the distance between the origins of the renal arteries 408,and the origin of the aortic aneurysmal sac 410 for proper implantplacement.

FIG. 6 is a continuation of the disclosed embodiment of the presentinvention of FIG. 5 in which the main implant delivery catheter sheath104 of the main implant delivery catheter 100 has been retracted orpartially opened to allow the endovascular implant 200 therein topartially open or unfold from its initially compressed or foldedposition. Additional contrast dye injection through the injector cannula404 may be performed by the operator at this point to verify the levelof the proximal circumferential sealable collar 112 with respect to thelevel of the renal arteries 408. FIG. 7 is a continuation of thedisclosed embodiment of the present invention of FIG. 6 in which thelevel of the proximal circumferential sealable collar 112 has beenadjusted by the operator with respect to the level of the renal arteries408 for optimal deployment.

FIG. 8 is a continuation of the disclosed embodiment of the presentinvention of FIG. 7 in which operator action on one or more proximalcontrol leads 120 connected to one or more proximal variable sealingdevices 116 has caused the proximal circumferential sealable collar 112of the elastic proximal end 108 of the endovascular implant 200 tofirmly and fully contact the aortic inner wall 124, effecting a vascularseal therein.

FIG. 9 is a continuation of the disclosed embodiment of the presentinvention of FIG. 8 in which operator action has fully retracted oropened and removed the main implant delivery sheath 104 of the mainimplant delivery catheter 100 allowing the endovascular implant 200therein to fully decompress or unfold, thus exposing a distal elasticimplant end 110 and a non-elastic contralateral cuff 126. At this pointin a deployment procedure, additional contrast dye injection wouldlikely again be performed to ascertain that there is a complete seal atthe level of the proximal circumferential sealable collar 112. Ifleakage is still visualized, additional operator action on the proximalcontrol lead (s) 120 may be used to further expand the proximalcircumferential sealable collar 112 to secure an acceptable seal.Alternately, operator action may reduce the expanded proximalcircumferential sealable collar 112 to allow its reposition andredeployment, again under real-time radiographic or other visualizedcontrol.

FIG. 10 is a continuation of the disclosed embodiment of the presentinvention of FIG. 9 once a suitable proximal seal has been achieved.Operator action on one or more distal control leads 122 connected to oneor more distal variable sealing devices 118 has caused the extendeddistal circumferential sealable collar 114 of the endovascular implant's200 elastic distal end 110 to firmly and fully contact the inner wall ofthe common iliac artery 412 above the origin of the internal iliacartery 414, effecting a vascular seal therein and preserving flowthrough the internal iliac artery 414. Additional contrast dye injectionthrough the injector cannula 404 would be used by the operator toconfirm adequate seals both proximally and distally at this point.

FIG. 11 is a continuation of the disclosed embodiment of the presentinvention of FIG. 10 in which operator action has placed a second guidewire 302 provided with an engagement tip 328 to grasp and stabilize thenon-elastic contralateral cuff 126 under radiographic or other imagingcontrol through an access via a second side through a femoralarteriotomy (not shown in FIG. 11).

FIG. 12 is a continuation of the disclosed embodiment of the presentinvention of FIG. 11 in which operator action has placed a contralateraldelivery catheter 300 over the second guide wire 302. The contralateraldelivery catheter 300 includes a contralateral delivery catheter lumen304 and a contralateral delivery catheter sheath 340 which may beoperably opened or retracted by operator action.

FIG. 13 is a continuation of the disclosed embodiment of the presentinvention of FIG. 12 in which operator action has removed thecontralateral delivery catheter sheath 340 of the contralateral deliverycatheter 300 allowing the endograft segmental implant 344 therein tofully decompress or unfold to expose a proximal segmental elasticimplant end 348, a distal segmental elastic implant end 356, and thefull length of a non-elastic segmental tubular implant body 346connecting said ends 348 and 356.

FIG. 14 is a continuation of the disclosed embodiment of the presentinvention of FIG. 13 in which operator action on one or more proximalsegmental control leads 354 connected to one or more proximal segmentalvariable sealing devices 352 has caused the expansion of proximalsegmental circumferential sealable collar 350 of the endograft segmentalimplant's 344 elastic proximal segmental implant end 348 to firmly andfully contact the inner walls of the non-elastic contralateral cuff 126effecting a proximal seal, and then similarly caused the distalsegmental circumferential sealable collar 358 of the endograft segmentalimplant's 344 elastic distal segmental implant end 356 to expand tofirmly and fully contact the inner wall of the common iliac artery 416on the second side above the origin of the internal iliac artery 418,effecting a vascular seal therein and preserving flow through theinternal iliac artery 418. Once sealed, the aortic aneurysmal sac 410 isdevascularized and collapses.

FIG. 15 shows a diagrammatic view of a patient 500 in a dorsal supineposition, with a disclosed embodiment of an endovascular implant 200according to the present invention in sealed position in the patient'sabdominal aorta 402 proximally and distally, and with arteriotomyincisions 332, 336 in both femoral arteries with an injector cannula 404for radiographic contrast dye injection and proximal 120 and distal 122control leads for operator manipulation in place in the patient's rightarteriotomy site 332 and a second guide wire 302 in place in thepatient's left arteriotomy site 336, corresponding to the proceduralstage shown in FIG. 11.

FIG. 16 shows an anatomic view of a disclosed embodiment of a thoracicendovascular implant 600 according to the present invention in sealedposition proximally and distally in a patient's descending thoracicaorta 612, traversing a devascularized thoracic aortic aneurysm 614. Ina patient, the ascending aorta 604 arises from the heart 602 and givesrise to the innominate artery 606, the left common carotid artery 608,and the left subclavian artery 610 before continuing as the descendingthoracic aorta 612. The thoracic endovascular implant 600 includes anon-elastic tubular thoracic implant body 616 with an elastic proximalthoracic end 618 and an elastic distal thoracic end 626. The elasticproximal thoracic end 618 terminates in a proximal thoracic sealablecircumferential collar 620, controlled by a proximal thoracic variablesealing device 622 which is operated by a proximal thoracic control lead624 that traverses a thoracic implant delivery catheter (not shown inFIG. 16) and exits distally for interface with an operator (not shown inFIG. 16). The elastic distal thoracic end 626 terminates in a distalsealable thoracic circumferential collar 628, controlled by a distalthoracic variable sealing device 630 which is operated by a distalthoracic control lead 632 that exits a thoracic implant deliverycatheter distally for interface with an operator (not shown in FIG. 6).

FIG. 17 provides an anatomic view showing an alternate disclosedembodiment of a thoracic endovascular implant 700 in a patient'sdescending thoracic aorta 612 according to the present invention inwhich a first thoracic endovascular implant 718 includes a non-elasticdistal cuff 730, a proximal first thoracic circumferential sealablecollar 724, a proximal first thoracic variable sealing device 726, and aproximal first thoracic control lead 728. As shown in FIG. 17, the firstthoracic endovascular implant 718 has been sealed in position proximallyby operator action on the proximal first thoracic variable sealingdevice 726 using the proximal first thoracic control lead 728, expandingthe proximal first thoracic circumferential sealable collar 724 toachieve a proximal seal within the descending thoracic aorta 612, andeffectively devascularizing a thoracic aneurysm 614 therein.

As further shown in FIG. 17, the first thoracic endovascular implant 718has been joined distally by a second thoracic endovascular implant 732,which includes an elastic proximal second thoracic implant end 736, anon-elastic tubular second thoracic implant body 734, and an elasticdistal second thoracic implant end 746. The elastic proximal secondthoracic implant end 736 includes a proximal second thoraciccircumferential sealable collar 738, a proximal second thoracic variablesealing device 740, and a proximal second thoracic control lead 742, andthe elastic distal second thoracic implant end 746 includes a distalsecond thoracic circumferential sealable collar 748, a distal secondthoracic variable sealing device 750, and a distal second thoraciccontrol lead 752.

In an exemplary application according to the present invention as shownin FIG. 17, an operator would first secure a seal in the proximaldescending thoracic aorta using the first thoracic endovascular implant718, and then seal the proximal and distal aspects, respectively, of thesecond thoracic endovascular implant 732, using real-time radiographicor other visualization techniques with injected contrast dye aspreviously described in this disclosure.

FIGS. 18A and 18B show an embodiment of an endovascular implantaccording to the present invention similar to the disclosure of FIG. 1B,with the additional inclusion of one of more retention tines 136attached to the proximal circumferential sealable collar 112 and distalcircumferential sealable collar 114.

In a preferred embodiment according to the present invention, aplurality of retention tines 136 is used. In a preferred embodimentaccording to the present invention, the retention tines 136 are orientedto extend radially outward from the proximal circumferential sealablecollar 112 and distal circumferential sealable collar 114. In variouspreferred embodiment according to the present invention, the retentiontines 136 may be oriented to extend perpendicularly or at any otherdesired angle outward from the proximal circumferential sealable collar112 and distal circumferential sealable collar 114.

In various preferred embodiment according to the present invention, theretention tines 136 may be constructed of any biocompatible materialincluding, but not limited to, metals, plastics, or ceramics.

As further shown in FIG. 18B the retention tines 136 of the proximalcircumferential sealable collar 112 and distal circumferential sealablecollar 114 covered by a compressible foam sheathing 134 in apre-deployment position. In various preferred embodiment according tothe present invention, the compressible foam sheathing 134 may beconstructed of any biocompatible material of suitable compressibility toallow the foam to be substantially compressed by the pressure of theproximal circumferential sealable collar 112 and distal circumferentialsealable collar 114 against the inner wall of a target artery, uponoperator deployment. The compressible foam sheathing 134 may also beconstructed of material of suitable memory characteristics to allow thefoam to substantially decompress to its pre-deployment position,covering the retention tines 136, if pressure against the arterial wallis removed, thus allowing repositioning or removal of an endovascularimplant according to the present invention at the operator's discretion.

Compressible foam sheathing 134 may be any biocompatible foam materialof either an open or closed cell structure with sufficientcompressibility and resilience to allow rapid recovery in anon-compressed state. In various preferred embodiments according to thepresent invention, such foam materials may be viscoelastic foam with acompressible cellular material that has both elastic (spring-like) andviscous (time-dependent) properties. Viscoelastic foam differs fromregular foam by having time-dependent behaviors such as creep, stressrelaxation, and hysteresis.

FIGS. 19A and 19B show the exemplary endovascular implant of FIGS. 18Aand 18B in the anatomic context of an endovascular implant 200 beingdeployed and sealed proximally in an abdominal aorta 402 containing ananeurysm 410, with complete expansion and seal at the level of theproximal circumferential sealable implant collar 112 against the aorticinner wall 124, but incomplete expansion and no seal against thearterial inner wall 144 at the level of the distal circumferentialsealable implant collar 114 at this stage of the procedure. As shown inthe cross-sectional view of FIG. 19B, the retention tines 136 of theproximal circumferential sealable collar 112 and distal circumferentialsealable collar 114 are covered by a compressible foam sheathing 134 ina pre-deployment position.

FIGS. 20A and 20B further show the exemplary endovascular implant ofFIGS. 18A and 18B in the anatomic context of an endovascular implant 200being deployed and sealed proximally in an abdominal aorta 402containing an aneurysm 410, now with complete expansion of the distalcircumferential sealable implant collar 114 and complete seal againstthe arterial inner wall 144 at this stage of the procedure. As shown inthe cross-sectional view of FIG. 20B, compressible foam sheathing 134 iscompressed between the distal circumferential sealable collar 114 andthe arterial inner wall 144, allowing the retention tines 136 to engagethe arterial inner wall 144 in their deployed position, thereby servingto retain the deployed position of the endovascular implant 200.

In given various preferred embodiments according to the presentinvention, retention tines 136 and the compressible foam sheathing 134as described above may be used in conjunction with any or allcircumferentially sealable elements in this disclosure, including butnot limited to, proximal circumferential sealable collars 112, distalcircumferential sealable collars 114, proximal segmental circumferentialsealable collars 314, distal segmental circumferential sealable collars316, proximal thoracic circumferential sealable collars 620, distalthoracic circumferential sealable collars 628, proximal first thoraciccircumferential sealable collars 724, proximal second thoraciccircumferential sealable collars 738, and distal second thoraciccircumferential sealable collars 748.

FIGS. 21A-D illustrate details of an embodiment of a variable sealingdevice according to the present invention. A variable sealing mechanismassembly 2100 comprises a sealing device housing 2102 attached to asealer belt 2104 with a sealer belt fixed end 2108 attached to saidhousing 2102 and with a sealer belt moveable end 2110 operably passingthrough said housing and collecting in a concentric belt receiverchannel 2130 as said sealer belt moveable end 2110 exits said housing2102. The sealer belt moveable end 2110 contains a plurality ofuniformly distributed belt engagement slots 2106. The belt engagementslots 2106 may be round, oval, square, rectangular, triangular, or anyother shape, but are sized, spaced, and configured on said sealer beltmoveable end 2110 to engage with sealer gear teeth 2116 of a sealer gear2114 rotatably located within a housing gear recess 2112 containedwithin said housing 2102. The sealer gear teeth 2116 are oriented topresent on the outer circumference of said sealer gear 2114. On theinner circumference of said sealer gear 2114, a plurality of uniformlydistributed sealer gear retainment slots 2118 are configured to receivea locking member 2120. The locking member 2120, in various embodimentsaccording to the present invention may be a simple strip or bar as shownin FIGS. 21A-D, or it may be triangular, cross-shaped, stellate or othergeometric shapes that would allow the sealer gear retainment slots 2118to receive the ends of said locking member 2120. The locking member 2120is fabricated of a metal or plastic with resilient spring-likeproperties, such that, when depressed or pulled in a perpendicularvector with respect to the sealer gear 2114, the ends of said lockingmember 2120 are withdrawn from the sealer gear retainment slots 2118,thus allowing the sealer gear 2114 to rotate within said housing gearrecess 2112, as shown in FIGS. 21B and C. The locking member 2120 isfurther provided with one or more sealer gear drive pins 2126, which arereceived in gear drive pin slots 2128 of said sealer gear 2114 when thelocking member 2120 is depressed, as shown in FIG. 21C. In variouspreferred embodiments according to the present invention, the gear drivepins 2126 and the gear drive pin slots 2128 may be tapered, straight, orotherwise shaped to facilitate their secure engagement and release. Thelocking member 2120 is depressed by action of a control lead shaft 2124,which is removably attached to the locking member 2120 at a control leadattachment 2122. In an exemplary embodiment of the present invention, asshown in FIG. 21C, while the locking member 2120 is released from thegear drive pin slots 2128 by a depressing action of the control leadshaft 2124, rotation of the control lead shaft 2124 will permit thesealer gear drive pins 2126 to transmit a rotational force to the sealergear 2114, engaging the belt engagement slots 2106 in the movable end ofthe sealer belt 2110, and causing the movable end of the sealer belt2110 to move in or out of the concentric belt receiver channel 2130.This motion has the effect of increasing or decreasing the surface areaof the sealer belt 2104.

FIG. 21D shows an exemplary embodiment according to the presentinvention, in which a sealable collar 2140 contains a variable sealingmechanism assembly 2100 comprising a sealing device housing 2102attached to a sealer belt 2104 with a sealer belt fixed end 2108attached to said housing 2102 and with a sealer belt moveable end 2110operably passing through said housing and collecting in a concentricbelt receiver channel 2130 as said sealer belt moveable end 2110 exitssaid housing 2102. The sealable collar 2140 is constructed of a tubularelastic body in a closed loop defining a central collar lumen 2142. Thesealer belt 2104 may pass circumferentially through substantially all ofthe sealable collar 2140, as shown in FIG. 21D, but in alternateembodiments may pass through only some of the circumference of thesealable collar 2140. As the variable sealing mechanism assembly 2100 isoperated, the length of the sealer belt 2104 may enlarge or constrict,with similar action on the sealable collar 2140, thus allowing avariable seal to be achieved between the sealable collar 2140 and theinner lumen of a vessel wall (not shown in FIG. 21D) containing thesealable collar 2140.

Within certain embodiments of the present invention, an endograft mayalso incorporate radio-opaque, echogenic materials and magneticresonance imaging (MRI) responsive materials (i.e., MRI contrast agents)to aid in visualization of the device under x-ray, ultrasound,fluoroscopy MRI or other imaging modalities. In addition, variousembodiments according to the present invention may incorporate markerscomprising various radio-opaque, echogenic materials and magneticresonance imaging (MRI) responsive materials that may be placed on thewalls of an aneurysm sac or on other anatomic sites for improvedpostoperative visualization to monitor for aneurysmal revascularization.

As shown in FIGS. 22A-22F, various embodiments according to the presentinvention may also be provided with one or more endograft monitoringdevices to facilitate diagnosis of postoperative graft failure andaneurysm revascularization. In some embodiments according to the presentinvention, endograft monitoring devices may be pressure sensorspositioned to demonstrate positive pressure within the former aneurysmalsac in some manner that may be identifiable by electronic, radiographic,or other visual or electronic communications. FIGS. 22A-F illustrate yetother embodiments of endograft monitoring devices according to thepresent invention.

FIGS. 22A-22B show an embodiment of a sealable vascular endograft system2200 which incorporates an endograft monitoring device comprising anradio-opaque graft attachment member 2205 joined at a monitoring pivot2210 to a radio-opaque aneurysmal attachment 2220 which is affixed by anoperator at the time of endograft placement to the inner wall of theaneurysmal sac 2215, which is shown in a collapsed, nonvascularizedstate in FIG. 22A, but in an expanded, revascularized state in FIG. 22B.As further shown in FIG. 22B, the expansion of the aneurysmal sac 2215,has the further effect of increasing the angle between the radio-opaquegraft attachment member 2205 and the radio-opaque aneurysmal attachment2220. In such an embodiment, plain radiographs or other visualizationmeans could be employed to evaluate the angle between the attachmentmembers of an endograft monitoring device to detect endograft failureand revascularization of the aneurysm without requiring more invasiveand expensive diagnostic studies.

FIGS. 22C and 22D illustrate yet another embodiment of an embodiment ofa sealable vascular endograft system 2200 which incorporates anendograft monitoring device comprising an radio-opaque graft attachment2202 pivotably joined by two or more radio-opaque graft frame members2212 which are in turn joined frame pivots 2204 to radio-opaqueaneurysmal frame members 2214 which are joined at an aneurysmalattachment 2216 which is affixed by an operator at the time of endograftplacement to the inner wall of the aneurysmal sac 2215, which is shownin a collapsed, nonvascularized state in FIG. 22C, but in an expanded,revascularized state in FIG. 22D. As further shown in FIG. 22D, theexpansion of the aneurysmal sac 2215, has the further effect ofincreasing the angles between the radio-opaque graft frame member 2212and the radio-opaque aneurysmal frame members 2214 to create a square orpolygonal shape visible on radiographs. In such an embodiment, plainradiographs or other visualization means could again be employed toevaluate the angles between the attachment members of an endograftmonitoring device to detect endograft failure and revascularization ofthe aneurysm without requiring more invasive and expensive diagnosticstudies.

FIGS. 22E and 22F illustrate still another embodiment of an embodimentof a sealable vascular endograft system 2200 which incorporates anendograft monitoring device comprising two or more radio-opaque graftattachment 2202 pivotably joined by two or more radio-opaque graft framemembers 2212 which are in turn joined frame pivots 2204 to radio-opaqueaneurysmal frame members 2214 which are joined at two or more aneurysmalattachments 2216 which are affixed by an operator at the time ofendograft placement to the inner wall of the aneurysmal sac 2215, whichis shown in a collapsed, nonvascularized state in FIG. 22E, but in anexpanded, revascularized state in FIG. 22F. As further shown in FIG.22F, the expansion of the aneurysmal sac 2215, has the further effect ofincreasing the angles between the radio-opaque graft frame member 2212and the radio-opaque aneurysmal frame members 2214 to create a square orpolygonal shape visible on radiographs. In such an embodiment,three-dimensional, cage-like structures could be formed by the variousframe members described, further enhancing the clinical visibility of anindication of aneurysmal revascularization.

Although the foregoing embodiments of the present invention have beendescribed in some detail by way of illustration and example for purposesof clarity and understanding, it will be apparent to those skilled inthe art that certain changes and modifications may be practiced withinthe spirit and scope of the present invention. Therefore, thedescription and examples presented herein should not be construed tolimit the scope of the present invention, the essential features ofwhich are set forth in the appended claims.

What is claimed is:
 1. A sealable vascular system, comprising: anendovascular implant to be delivered in a compressed or folded state toan implantation site, said endovascular implant including: a tubularimplant body; and a sealable circumferential collar at said tubularimplant body and including: a variable sealing device; and a controllead traversing from said variable sealing device to a user forcontrolling said variable sealing device by the user, said variablesealing device and said control lead being cooperatively operable toreversibly expand and contract said sealable circumferential collar suchthat said sealable circumferential collar is circumferentiallyadjustable during deployment thereof to achieve a repositionablefluid-tight seal between said sealable circumferential collar and theinternal walls of the implantation site.
 2. An endovascular implant forplacement in a vascular defect, the implant comprising: a tubularimplant body; a sealable circumferential collar at said tubular implantbody, said sealable circumferential collar including a variable sealingdevice operable to reversibly expand and contract said sealablecircumferential collar such that said sealable circumferential collar iscircumferentially adjustable during deployment thereof to achieve arepositionable fluid-tight seal between said sealable circumferentialcollar and internal walls of a blood vessel adjacent the vasculardefect; and a control lead connected to said variable sealing device,said control lead traversing from said variable sealing device to a userfor controlling said variable sealing device by the user.
 3. Theendovascular implant of claim 2, wherein said tubular implant body isnon-elastic.
 4. The endovascular implant of claim 2, wherein saidsealable circumferential collar is elastic.
 5. The endovascular implantof claim 2, wherein said sealable circumferential collar is a proximalsealable circumferential collar, and further comprising: a distalsealable circumferential collar at said distal end of said tubularimplant body, said distal sealable circumferential collar including adistal variable sealing device operable to reversibly expand andcontract said distal sealable circumferential collar such that saiddistal sealable circumferential collar is circumferentially adjustableduring deployment thereof to achieve a repositionable fluid-tight sealbetween said distal sealable circumferential collar and internal wallsof the blood vessel distal to the vascular defect.
 6. The endovascularimplant of claim 2, wherein: said tubular implant body is operable to behoused within a main implant delivery catheter having a catheterproximal end and a catheter distal end, the main implant deliverycatheter being operable to be disposed within the blood vessel todeliver said tubular implant body at the vascular defect; and saidcontrol lead is operable to traverse said main implant delivery catheterfrom said variable sealing device at least to said catheter proximal endwhen housed therein for interface by the user.
 7. The endovascularimplant of claim 2, wherein: said tubular implant body is operable to behoused within a main implant delivery catheter having a catheterproximal end and a catheter distal end, the main implant deliverycatheter being operable to be disposed within the blood vessel todeliver said tubular implant body at the vascular defect; said distalend of said tubular implant body further includes a distal variablesealing device and a distal control lead connected to said distalvariable sealing device; and said distal control lead is operable totraverse said main implant delivery catheter from said distal variablesealing device at least to said catheter proximal end when housedtherein for interface by the user.
 8. The endovascular implant of claim2, wherein said tubular implant body is straight.
 9. The endovascularimplant of claim 2, wherein said tubular implant body branches into twoor more branches.
 10. The endovascular implant of claim 2, wherein saidtubular implant body is a plurality of tubular implant bodies eachoperable to be connected to another of said tubular implant bodies in avariably sealable manner by operation of said sealable circumferentialcollars as controlled by said variable sealing devices, respectively, toachieve a repositionable fluid-tight seal between: a proximal-most oneof said sealable circumferential collars and the internal walls of theblood vessel proximal to the vascular defect; and a distal-most one ofsaid sealable circumferential collars and the internal walls of theblood vessel distal to the vascular defect.
 11. The endovascular implantof claim 2, wherein said tubular implant body is of: solid construction;and a biocompatible material.
 12. The endovascular implant of claim 2,wherein said tubular implant body is of: woven construction; and abiocompatible material.
 13. The endovascular implant of claim 2, whereinsaid endovascular implant is coated with a biocompatible material.
 14. Amethod of treating a vascular defect in a blood vessel within a patient,the method comprising: placing an elongated main implant deliverycatheter through a peripheral vascular entry into the blood vesselhaving internal walls, said implant delivery catheter having: a catheterproximal end and a catheter distal end; an implant delivery cathetersheath defining an implant delivery catheter lumen; and an endovascularimplant disposed within said implant delivery catheter lumen in acompressed or folded state, the endovascular implant having: a tubularimplant body having a proximal end and a distal end; and a sealablecircumferential collar at said tubular implant body including a variablesealing device having a control lead operatively connected thereto, saidcontrol lead being operable to traverse said implant delivery catheterfrom said variable sealing device at least to said catheter proximal endwhen housed therein for interface by a user; employing real-timevisualization to monitor implant placement in the blood vessel; distallyretracting said implant delivery catheter sheath to expose said proximalend of said endovascular implant; cooperatively manipulating saidcontrol lead and said variable sealing device to circumferentiallyadjust said sealable circumferential collar to achieve a fluid-tightseal between said sealable circumferential collar and the internal wallsof the blood vessel adjacent the vascular defect, said control lead andsaid variable sealing device being cooperatively operable to reversiblyexpand and contract said sealable circumferential collar such that thefluid-tight seal is repositionable; distally retracting said implantdelivery catheter sheath to expose said distal end of said endovascularimplant; and removing said control lead and said implant deliverycatheter through said peripheral vascular entry.
 15. The method of claim14, further comprising the step of connecting one or more additionalendovascular implants in a variably sealable manner by operation of saidsealable circumferential collars as controlled by said variable sealingdevices and control leads, respectively, to achieve a repositionablefluid-tight seal between: a proximal-most one of said sealablecircumferential collars and the internal walls of the blood vesselproximal to the vascular defect; and a distal-most one of said sealablecircumferential collars and the internal walls of the blood vesseldistal to the vascular defect.
 16. The method of claim 14, wherein thevascular defect is an aneurysm.
 17. The sealable vascular system ofclaim 1, wherein the vascular defect is an aneurysm.
 18. The sealablevascular system of claim 1, wherein said endovascular implant furthercomprises a retraction device operable to reposition said endovascularimplant during deployment.
 19. The endovascular implant of claim 2,further comprising a retraction device operable to reposition saidtubular implant body during deployment.
 20. The method of claim 14,wherein said endovascular implant further comprises a retraction deviceoperable to reposition said endovascular implant during deployment. 21.A system for circumferentially sealing within a lumen, comprising: animplant to be delivered in a compressed or folded state to animplantation site, the implant comprising: a tubular body having avariable circumferential-sealing collar; and a control lead traversingfrom said collar to a user for controlling said collar by the user, saidcollar and said control lead being cooperatively operable to reversiblyexpand and contract said collar such that said collar iscircumferentially adjustable during deployment thereof to achieve arepositionable fluid-tight seal between said collar and the implantationsite.
 22. A method of treating a vascular defect in a blood vesselwithin a patient, the method comprising: employing real-timevisualization to monitor placement of an endovascular implant in acompressed or folded state in the blood vessel, the endovascular implanthaving: a tubular implant body; a proximal end and a distal end; asealable circumferential collar at said tubular implant body including avariable sealing device; and a control lead operatively connected to thevariable sealing device and traversing therefrom to a user for interfaceby the user; and cooperatively manipulating said control lead and saidvariable sealing device to circumferentially adjust said collar toachieve a fluid-tight seal between said collar and the internal walls ofthe blood vessel, said control lead and said variable sealing devicebeing cooperatively operable to reversibly expand and contract saidcollar such that the fluid-tight seal is repositionable.